University of Vermont Extension
Department of Plant and Soil Science

Summer News
ArticlePLANTS TO ATTRACT BUTTERFLIES

Dr. Leonard Perry, Extension
Professor
University of Vermont

If you
love to watch butterflies in summer, perhaps you should think about
the plants
that attract them. More importantly,
realize that these and moths (together termed “lepidopterans”) don’t
exist for
our enjoyment, but to pollinate flowers and their larvae
(caterpillars) to
provide food for birds. In fact, such
larvae are one of the main sources of food for birds. With an
abundance of lepidopterans in your
landscape, you’ll likely attract many birds as a benefit too. These
birds, in addition to their sights and
songs, provide an “ecological service” by eating many other insects.

Professor
Doug Tallamy of the University of Delaware, has written a book—Bringing
Nature Home-- describing in
some detail the benefits of insects in our landscapes, as well as
how most are
attracted to and prefer native plants. He
and assistants have compiled a very complete and extensive listing
of species
of plants and lepidopterans from the mid-Atlantic states, which of
these insects
are attracted to which plants, and they ranked the most important
plants (udel.edu/~dtallamy/host/). While these numbers all won’t
fit exactly in
northeastern states, most of the plants grow here as well, and many
of the key
plants are likely important here too.

While
there are many other insects that pollinate plants (such as bees),
and provide
food for birds, they chose to focus on this large group of moths and
butterflies (about 3,500 species in the mid-Atlantic states). In
their lists they considered 1385 plant
genera (the large groupings of plants such as asters, goldenrod, bee
balm, and
the like). Of these, there were 884 native plant genera, and 501
non-natives or
introduced plants from elsewhere (“exotics” or “aliens”).

In
their ranking list of woody plants, only one non-native (pears) was
in the top
50 most attractive to moths and butterflies.
In their listing of herbaceous plants, 16 non-natives were in the
top 50
most attractive, while the rest were native plants. Of the
introduced herbaceous plants that
attract moths and butterflies, these non-natives included a few
“weeds” such as
dandelion (87 different lepidopterans attracted to this in the
mid-Atlantic
states, including both native and non-native species) and burdock
(27); only
one common garden flower—the hollyhock (22); some common vegetables
such as corn
(120), Brussel’s sprouts (68), beets (44), peas (38), and asparagus
(32); and
main agronomic crops such as alfalfa (69), wheat (36), and soybean
(33).

In
the top 50 most attractive list of native herbaceous plants, fruits
and
vegetables included strawberries (81), beans (66), and lettuce
(51). Native “weeds” that you might consider
leaving, at least in a few out-of-sight or controlled areas, that
attract moths
and butterflies, include plantain (66), horsenettle (61), ragweed
(48),
lambsquarters (42), nettle (35), pigweed (29), and thistle (29). If
your garden
gets weedy, just tell visitors it is providing an “ecological
service”, or that
it is a butterfly garden.

Of
course, in each of these plant genera there are several if not many
species,
not all of which may be most attractive, nor even all native. But
these are a good selection to choose from
with a good chance of helping and attracting butterflies more than
many other
plants. For the total species listed
attracted to these plants, you’ll find many more native moths and
butterflies
in the lists than non-natives. For
instance, for oaks, of the 532 species attracted, 14 are exotic and
518 are
natives. For clover, of the 122 species attracted, 7 are exotic and
115 are
natives.

In
addition to the flowers already listed, other favorite plants for
butterflies
and moths include Joe-pye, honeysuckle, black-eyed susan, iris,
evening
primrose, milkweed, verbena, penstemon, phlox, bee balm, speedwell,
and
lobelia. You can read much more on why
native plants are important in our landscapes, and what to plant in
landscapes,
at Professor Tallamy’s website (bringingnaturehome.net). Lists,
searchable by state and trait, for not
only moths and butterflies but bees too, can be found from the Lady
Bird
Johnson Wildflower Center (www.wildflower.org).